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Full-Text Articles in Civil and Environmental Engineering

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman Sep 2015

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10–6 occurs for …


Evaluation Of Deterioration Of Structural Concrete Due To Chloride Intrusion And Other Damaging Mechanisms, Sudhir Palle, Brian K. Howell, Theodore Hopwood Ii, Bobby W. Meade Sep 2015

Evaluation Of Deterioration Of Structural Concrete Due To Chloride Intrusion And Other Damaging Mechanisms, Sudhir Palle, Brian K. Howell, Theodore Hopwood Ii, Bobby W. Meade

Kentucky Transportation Center Research Report

Kentucky's bridges continue to age and experience distress. The intrusion of chlorides into concrete remains the primary mechanism for deterioration. It leads to reinforcing steel corrosion that damages the adjoining concrete structure. This study found problematic chloride concentrations in Kentucky concrete bridge elements (decks, pier caps, abutments). Chloride levels have been found at concentrations sufficient to initiate reinforcing steel corrosion. In some cases, chloride concentrations were sufficient to cause accelerated corrosion and produce major section loss of reinforcing steel. Advanced stages of corrosion such as these typically require costly repairs and maintenance to extend the service life of bridges.

Field …


Analysis Of Historical Travel Time Data, Mei Chen, Xu Zhang, Eric R. Green Sep 2015

Analysis Of Historical Travel Time Data, Mei Chen, Xu Zhang, Eric R. Green

Kentucky Transportation Center Research Report

Travel speed is a critical piece of information for many applications. The Moving Ahead for Progress in the 21st Century Act (MAP-21) states that calculating travel speeds illuminates the performance of the nation’s highway system. New technologies make the collection of speed data more straightforward than ever. Private vendors collect and sell this data, and KTC purchased speed data for 2010-2013 from NAVTEQ (now HERE). The main objectives of the research were to:

  • Evaluate private sector speed data and its use in generating travel time based performance measures
  • Create a mechanism to integrate this speed data with networks maintained by …


Online Driver’S License Renewal, Valerie J. Keathley, Andrew Martin, Jennifer R. Walton Sep 2015

Online Driver’S License Renewal, Valerie J. Keathley, Andrew Martin, Jennifer R. Walton

Kentucky Transportation Center Research Report

The Kentucky Department of Vehicle Regulation is exploring the possibility of developing and implementing online driver’s license renewal. The objective of this project was to: 1) evaluate online driver’s license and REAL ID renewal programs in other states to identify best practices; 2) examine two options to institute online renewal; and 3) identify what legislative changes would be required in Kentucky to authorize an online renewal program. KTC surveyed 25 states with online license renewal programs in place, and received responses from 14 states. Survey respondents indicated that online renewal is more efficient, improves customer service, cuts down on foot …


Analysis Of Traffic Crash Data In Kentucky (2010-2014), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman, Michael A. Fields Sep 2015

Analysis Of Traffic Crash Data In Kentucky (2010-2014), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman, Michael A. Fields

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 2010 through 2014. A primary objective of this study was to determine average crash statistics for Kentucky highways. Rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.


Work Vehicle Warning Lights: Color Options And Effectiveness, Brian K. Howell, Jerry G. Pigman, Kenneth R. Agent Sep 2015

Work Vehicle Warning Lights: Color Options And Effectiveness, Brian K. Howell, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

KTC reviewed existing regulations, guidance, and practices to assess the Kentucky Transportation Cabinet’s warning lights program on highway work vehicles. The Kentucky Revised Statutes categorizes KYTC vehicles as “public safety vehicles” and requires their use of amber lights. Because the use of red can be confused with emergency vehicles, KYTC prohibits the use of red on work vehicles. At the national level, standards for warning light colors do not exist. Rather, AASHTO provides guidance on roadway operations equipment and recommends the use of amber and white lights as the primary warning light colors for highway vehicles. AASHTO guidance also prescribes …


Water Expert: A Conceptualized Framework For Development Of A Rule-Based Decision Support System For Distribution System Decontamination, J. L. Gutenson, A. N. S. Ernest, J. R. Fattic, L. E. Ormsbee, A. A. Oubeidillah, X. Zhang Aug 2015

Water Expert: A Conceptualized Framework For Development Of A Rule-Based Decision Support System For Distribution System Decontamination, J. L. Gutenson, A. N. S. Ernest, J. R. Fattic, L. E. Ormsbee, A. A. Oubeidillah, X. Zhang

Civil Engineering Faculty Publications

Significant drinking water contamination events pose a serious threat to public and environmental health. Water utilities often must make timely, critical decisions without evaluating all facets of the incident. The data needed to enact informed decisions are inevitably dispersant and disparate, originating from policy, science, and heuristic contributors. Water Expert is a functioning hybrid decision support system (DSS) and expert system framework that emphasizes the meshing of parallel data structures in order to expedite and optimize the decision pathway. Delivered as a thin-client application through the user's web browser, Water Expert's extensive knowledgebase is a product of inter-university collaboration …


Effect Of Thermal Loads On Substructures: New Trammel Creek Bridge On Ky-100 In Allen County, Kentucky, Zhihui Zhu, Michael T. Davidson, Issam E. Harik, Charlie Sun Aug 2015

Effect Of Thermal Loads On Substructures: New Trammel Creek Bridge On Ky-100 In Allen County, Kentucky, Zhihui Zhu, Michael T. Davidson, Issam E. Harik, Charlie Sun

Kentucky Transportation Center Research Report

When infrastructure is subjected to temperature changes, structural members that are either partially or fully restrained against motion can develop internal stresses. The phenomenon of temperature-induced internal stress development in superstructure members has prompted the American Association of State Highway and Transportation Officials (AASHTO) to include provisions for determining superstructure temperature load effects. However, little consideration has been given to explicitly quantifying the effect that thermal stresses have on foundation systems such as intermediate bridge piers. The objective of this study is to instrument a multi-span integral abutment bridge with temperature and bridge response monitoring devices, and ultimately, to make …


2015 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Michael A. Fields Aug 2015

2015 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Michael A. Fields

Kentucky Transportation Center Research Report

The objective of the survey summarized in this report was to establish a statewide safety belt usage rate in Kentucky for 2015. This rate can be compared to those determined from previous surveys. The 2015 statewide survey documents the continued increase in usage associated with the change in the law to allow primary enforcement and related education and enforcement.


Spatial Database For Intersections, Eric R. Green, Christopher L. Blackden, Michael A. Fields Aug 2015

Spatial Database For Intersections, Eric R. Green, Christopher L. Blackden, Michael A. Fields

Kentucky Transportation Center Research Report

Deciding which intersections in the state of Kentucky warrant safety improvements requires a comprehensive inventory with information on every intersection in the public roadway network. The Kentucky Transportation Cabinet (KYTC) had previously catalogued only those intersections where state-maintained roadways met. However, this inventory did not account for intersections between state- and locally-maintained routes, nor was it designed to accommodate regular updates. As such, the Kentucky Transportation Center (KTC) at the University of Kentucky developed a methodology to create and maintain a full inventory of every intersection in the state. The database contains precise location information as well as several safety …


Synthesis Of Public-Private Partnerships: Potential Issues And Best Practices For Program And Project Implementation And Administration, Bryan Gibson, Candice Y. Wallace, Roy E. Sturgill Aug 2015

Synthesis Of Public-Private Partnerships: Potential Issues And Best Practices For Program And Project Implementation And Administration, Bryan Gibson, Candice Y. Wallace, Roy E. Sturgill

Kentucky Transportation Center Research Report

Public-private partnerships (P3s or PPPs) offer an innovative procurement method for the public sector. P3s involve collaborations between the public and private sectors to finance, develop or maintain transportation infrastructure. In an era of shrinking budgets and increased demand for transportation infrastructure, the Kentucky Transportation Cabinet (KYTC) can analyze experiences in other states to determine a best path forward on the issue of P3s. The objective of this study is to examine benefits and drawbacks of using P3s, current trends and past performance of P3s in the procurement of state transportation infrastructure projects, and common legislative statutes relating to P3s. …


A Gis-Based Expert Systems Predictive Habitat Model For Threatened And Endangered Species: Case Study Using Kentucky Arrow Darter, Benjamin L. Blandford, Michael Shouse, John Ripy Aug 2015

A Gis-Based Expert Systems Predictive Habitat Model For Threatened And Endangered Species: Case Study Using Kentucky Arrow Darter, Benjamin L. Blandford, Michael Shouse, John Ripy

Kentucky Transportation Center Research Report

This study presents a GIS-based predictive habitat suitability model for the Kentucky arrow darter (Etheostoma spilotum), a fish species of the upper Kentucky River basin that is a candidate for federal listing by the U.S. Fish and Wildlife Service. The model is based on previous work: the development of a similar predictive model for identifying the habitat of the blackside dace, a threatened minnow species of the upper Cumberland River basin in Southeastern Kentucky. The research describes a weighted, rules-based system which incorporates expert knowledge about habitat preferences for the arrow darter. For this model, five habitat factors …


Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng Jul 2015

Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng

Chemistry Faculty Publications

The formation of secondary organic aerosol (SOA) from the oxidation of β-pinene via nitrate radicals is investigated in the Georgia Tech Environmental Chamber (GTEC) facility. Aerosol yields are determined for experiments performed under both dry (relative humidity (RH) < 2 %) and humid (RH = 50 % and RH = 70 %) conditions. To probe the effects of peroxy radical (RO2) fate on aerosol formation, "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are performed. Gas-phase organic nitrate species (with molecular weights of 215, 229, 231, and 245 amu, which likely correspond to molecular formulas of C10H17NO4, C10H15NO5, C10H17NO …


Preventive Maintenance Program For Bridges, Theodore Hopwood Ii, Jared Fairchild, Bobby W. Meade, Sudhir Palle Jul 2015

Preventive Maintenance Program For Bridges, Theodore Hopwood Ii, Jared Fairchild, Bobby W. Meade, Sudhir Palle

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet’s (KYTC) bridge inventory is rapidly aging. As such, the Cabinet needs to identify and implement relevant preventative maintenance (PM) actions to extend the useful service lives of those structures. Maintenance actions, costs, and application interval/repair durability information have been obtained for both cyclical and condition - based bridge PM. Additionally, information rehabilitation actions were acquired from a regional DOT survey and from other literature. As part of this study, the Kentucky Transportation Center (KTC) researchers monitored a KYTC bridge washing project to assess its level of effectiveness and to identify potential improvements. Based upon these tasks, …


Jurisdictional Roadside Ditches, Sarah M. Mccormack, Christopher W. Van Dyke, Doug Kreis Jun 2015

Jurisdictional Roadside Ditches, Sarah M. Mccormack, Christopher W. Van Dyke, Doug Kreis

Kentucky Transportation Center Research Report

Section 404 of the Clean Water Act (CWA) mandates that state agencies and other entities perform compensatory mitigation when their activities impair jurisdictional waters. In the Commonwealth of Kentucky, the Kentucky Transportation Cabinet (KYTC) is required to pay in-lieu fees or purchase stream mitigation credits when a roadside ditch is impaired or relocated as part of a road construction project. In-lieu fees and stream mitigation credits are costly, and ditches that have suffered degraded habitat and loss of hydrogeomorphic functionality are treated as total losses when they are impacted by construction and maintenance activities. This raises the question of whether …


Isotope-Based Fluvial Organic Carbon (Isofloc) Model: Model Formulation, Sensitivity, And Evaluation, William I. Ford, James F. Fox Jun 2015

Isotope-Based Fluvial Organic Carbon (Isofloc) Model: Model Formulation, Sensitivity, And Evaluation, William I. Ford, James F. Fox

Civil Engineering Faculty Publications

Watershed-scale carbon budgets remain poorly understood, in part due to inadequate simulation tools to assess in-stream carbon fate and transport. A new numerical model termed ISOtope-based FLuvial Organic Carbon (ISOFLOC) is formulated to simulate the fluvial organic carbon budget in watersheds where hydrologic, sediment transport, and biogeochemical processes are coupled to control benthic and transported carbon composition and flux. One ISOFLOC innovation is the formulation of new stable carbon isotope model subroutines that include isotope fractionation processes in order to estimate carbon isotope source, fate, and transport. A second innovation is the coupling of …


Forensic Pavement Evaluation For Us 31 W, Jefferson County, Kentucky Using Ground Penetrating Radar, Brad W. Rister, Kean Ashurst, R. Clark Graves Apr 2015

Forensic Pavement Evaluation For Us 31 W, Jefferson County, Kentucky Using Ground Penetrating Radar, Brad W. Rister, Kean Ashurst, R. Clark Graves

Kentucky Transportation Center Technical Assistance Report

The Kentucky Transportation Center (KTC) utilized ground penetrating radar technology to provide a forensic evaluation of the existing pavement structure for the US31W pavement rehabilitation Project in Jefferson County, KY. Processed ground penetrating radar data indicated that the integrity of the underlying concrete pavement beneath the asphalt pavement appears to be competent and structurally sound. The clay soil beneath the concrete pavement appears relatively dry and well compacted. The analyzed GPR data also indicated that the average asphalt layer varied by lane throughout the project from 4.89 to 7.59 inches +/- ½ inch and that the underlying concrete layer average …


Hydrodemolition And Use Of A Rapid Early Strength Latex Modified Concrete Overlay, Theodore Hopwood Ii, Christopher Goff, Danny Wells, Sudhir Palle Apr 2015

Hydrodemolition And Use Of A Rapid Early Strength Latex Modified Concrete Overlay, Theodore Hopwood Ii, Christopher Goff, Danny Wells, Sudhir Palle

Kentucky Transportation Center Technical Assistance Report

On July 11, 2014, KYTC held a letting for the hydro demolition of two bridge decks on I-64 in Franklin County - main-line twin bridges over Cardwell Lane MP 51.516 (Contract ID 143915; Fed/State Project No. IM 0643(052)). The special notes for the project are provided in Appendix A. The tabulation of bids is provided in Appendix B. Five bids were received ranging from $787,836.00 to $1,082,639.46. The contract was awarded to the lowest bidder, Halls Contracting. Each bridge is 30 ft. wide and 159 ft. long, with for a total area of 4,770 ft. The type 104 bridges have …


Highway Rail Crossing Prioritization, Bryan Gibson, Reginald R. Souleyrette Mar 2015

Highway Rail Crossing Prioritization, Bryan Gibson, Reginald R. Souleyrette

Kentucky Transportation Center Technical Assistance Report

Research team members at the University of Kentucky in the Department of Civil Engineering and the Kentucky Transportation Center (KTC) worked with the Kentucky Transportation Cabinet (KYTC) to develop a high-level mechanism for ranking highway-rail crossings for reconstruction and/or rehabilitation. The Highway Rail Crossing Prioritization implementation study yielded the Rail Crossing Improvement Priority (RCIP), which combined qualitative measures of crossing conditions with quantitative measures including proposed project costs and a valuation of the crossing based on rail and truck traffic. This effort provides a template by which further development can yield prioritization procedures for road-rail grade separation projects.


Assessment Program For Kentucky Traffic Records, Lenahan O'Connell, Eric R. Green, Reginald R. Souleyrette Feb 2015

Assessment Program For Kentucky Traffic Records, Lenahan O'Connell, Eric R. Green, Reginald R. Souleyrette

Kentucky Transportation Center Research Report

During 2013, the Kentucky Transportation Center identified 117 potential performance metrics for the ten databases in the Kentucky Traffic Records System. This report summarizes the findings of three main tasks completed in 2014: (1) assessment of the utility of each metric and/or the availability of data; (2) collection of data on the metrics deemed useful with available data; and (3) assessment the possibility of incorporating a number of the Model Minimum Uniform Crash Criteria (MMUCC) elements into the CRASH database. Interviews with liaisons for each database reduced the number of metrics from 117 to 51. The reason for rejecting the …


Multistage Concentration Of Cenospheres In Fly Ash Using The Inverted Reflux Classifier, A. Kiani, J. Zhou, K.P. Galvin Jan 2015

Multistage Concentration Of Cenospheres In Fly Ash Using The Inverted Reflux Classifier, A. Kiani, J. Zhou, K.P. Galvin

Coal Combustion and Gasification Products Journal Archive

Cenospheres are one of the most valuable components found in the fly ash waste of coal-fired power stations, consisting of hollow, aluminosilicate spherical shells and offering very low bulk density, high strength, and high thermal resistance. Although wet processing methods offer the best prospect for achieving recovery and concentration of the cenospheres, significant impediments remain for achieving satisfactory economics. This work was concerned with the recovery and concentration of cenospheres from fly ash using a novel system, the inverted reflux classifier (IRC), covering single and multistage processing. The system consists of a series of parallel inclined channels mounted underneath an …


Strengthening Black Cotton Soil With Fly Ash And Moorum: An Investigation Of The Role Of Subgrade And Subbase Layers, Gourav Saxena, Nikhlesh Chaurasia Jan 2015

Strengthening Black Cotton Soil With Fly Ash And Moorum: An Investigation Of The Role Of Subgrade And Subbase Layers, Gourav Saxena, Nikhlesh Chaurasia

Coal Combustion and Gasification Products Journal Archive

One of the most effective and economical methods to strengthen clayey soils is addition of stabilizing agents such as fly ash to the soil. In this study, highly plastic clay was stabilized using fly ash. Geotechnical properties such as Atterberg limits, unconfined compressive strength (UCS), and the California bearing ratio (CBR) value of virgin black cotton soil and soil treated with fly ash were evaluated. Soil was stabilized with various proportions of fly ash, i.e., at 0%, 10%, 15%, 20%, and 30%. The UCS of black cotton soil–fly ash mixes is found to be at its maximum at 20% fly …


Using Coal Fly Ash In Agriculture: Combination Of Fly Ash And Poultry Litter As Soil Amendments For Bioenergy Feedstock Production, E. Kudjo Dzantor, Ekundayo Adeleke, Vanaha Kankarla, Oluwatosin Ogunmayowa, Dafeng Hui Jan 2015

Using Coal Fly Ash In Agriculture: Combination Of Fly Ash And Poultry Litter As Soil Amendments For Bioenergy Feedstock Production, E. Kudjo Dzantor, Ekundayo Adeleke, Vanaha Kankarla, Oluwatosin Ogunmayowa, Dafeng Hui

Coal Combustion and Gasification Products Journal Archive

Increasing fiscal, human, and environmental costs of coal fly ash (FA) management are leading to advocacy for greater beneficial uses of the by-products as soil amendments in agriculture. Greenhouse experiments were conducted in Armour silt loam (ASL) soil that was amended with FA (10%, wt/wt) with and without poultry litter (PL 5 75 mg N/kg). Biomass productivity of eastern gamagrass (GG), a warm-season perennial grass, was measured to serve as complementary biofuel feedstock to switchgrass (SG). FA was obtained from a site at the 2008 ash spill in Kingston, TN. GG and SG were grown individually in 15-cm-wide 3 41-cm-high …


Vibration Of Steel-Framed Floors Supporting Sensitive Equipment In Hospitals, Research Facilities, And Manufacturing Facilities, Di Liu Jan 2015

Vibration Of Steel-Framed Floors Supporting Sensitive Equipment In Hospitals, Research Facilities, And Manufacturing Facilities, Di Liu

Theses and Dissertations--Civil Engineering

Floors have traditionally been designed only for strength and deflection serviceability. As technological advances have been made in medical, scientific and micro-electronics manufacturing, many types of equipment have become sensitive to vibration of the supporting floor. Thus, vibration serviceability has become a routinely evaluated limit state for floors supporting sensitive equipment. Equipment vibration tolerance limits are sometimes expressed as waveform peak acceleration, and are more often expressed as narrowband spectral acceleration, or one-third octave spectral velocity.

Current floor vibration prediction methods, such as those found in the American Institute of Steel Construction Design Guide 11, Floor Vibrations Due to Human …


The Applicability Of Western Management In The Middle East, Zamaan Al-Shabbani Jan 2015

The Applicability Of Western Management In The Middle East, Zamaan Al-Shabbani

Theses and Dissertations--Civil Engineering

The Middle Eastern construction industry is still suffering from cost overruns, delays, and disputes. Inefficient management practices and lack of management are frequently reported reasons for such problems. Researchers attribute such problems to the traditional management practices that are utilized in the Middle East. However, International companies who practice their best management strategies are still suffering from the same problems. These issues become more significant in joint ventures when two different management styles work together. Therefore, it becomes crucial to understand the characteristics of Middle Eastern construction environment in terms of the management practices and regulations that are used and …


Life-Cycle Cost Analysis Of Reinforced Concrete Bridges Rehabilitated With Cfrp, Jeffrey L. Smith Jan 2015

Life-Cycle Cost Analysis Of Reinforced Concrete Bridges Rehabilitated With Cfrp, Jeffrey L. Smith

Theses and Dissertations--Civil Engineering

The deterioration of highway bridges and structures and the cost of repairing, rehabilitating, or replacing deteriorated structures is a major issue for bridge owners. An aging infrastructure as well as the need to upgrade structural capacity for heavier trucks adds to problem. Life-cycle cost analysis (LCCA) is a useful tool for determining when the deployment of fiber-reinforced polymer (FRP) composite components is an economically viable alternative for rehabilitating deteriorated concrete bridges.

The use of LCCA in bridge design and rehabilitation has been limited. The use of LCCA for bridges on a project level basis has often been limited to the …


Commercialization Of A Small, Lightweight, Low-Cost Seismic Borehole Receiver, Rachel Adams Jan 2015

Commercialization Of A Small, Lightweight, Low-Cost Seismic Borehole Receiver, Rachel Adams

Theses and Dissertations--Civil Engineering

Herein, conceptualization of a recently patented seismic borehole receiver and its components is developed for commercialization. The device is significantly cheaper, lighter, and smaller than existing technologies on the market. Additionally, it has the potential to achieve better seismic readings than its competitors via patented sensor-to-borehole coupling mechanism. It is the hope that the commercialization of this device will not only provide a more affordable alternative to engineers and geophysicists in the existing market, but the significant cost difference may open new seismic measurement opportunities in the developing world. Its compact size and light weight will increase mobility, allowing investigators …


Sediment Organic Carbon Fate And Transport In A Fluviokarst Watershed In The Bluegrass Region, Admin Husic Jan 2015

Sediment Organic Carbon Fate And Transport In A Fluviokarst Watershed In The Bluegrass Region, Admin Husic

Theses and Dissertations--Civil Engineering

Mature karst topography is well recognized within the hydrology and geology communities to include subterranean fluid pathways that act as turbulent conduits conveying fluid from surface stream sinks called swallets to sources called springs. However, we find that little knowledge has been reported with regards to the transport and fate of terrestrially-derived sediment organic carbon (SOC) within karst watersheds. This study investigated the hypothesis that karst pathways could act as biologically active conveyors of SOC that temporarily store sediment, turnover carbon at higher rates than otherwise considered, and recharge depleted SOC back to the surface stream within the fluvial system. …


Fabrication And Testing Of Low-Energy Calcium Sulfoaluminate-Belite Cements That Utilize Circulating Fluidized Bed Combustion By-Products, Robert Jewell, Robert Rathbone, Tristana Duvallet, Thomas Robl, Kamyar Mahboub Jan 2015

Fabrication And Testing Of Low-Energy Calcium Sulfoaluminate-Belite Cements That Utilize Circulating Fluidized Bed Combustion By-Products, Robert Jewell, Robert Rathbone, Tristana Duvallet, Thomas Robl, Kamyar Mahboub

Coal Combustion and Gasification Products Journal Archive

The utilization of circulating fluidized bed combustion (CFBC) ash to make cement products that provide added value and offset CO2 production is the objective of this research. CFBC burns coal in the presence of a bed of slaked limestone, which effectively absorbs sulfur dioxide (SO2) to form anhydrite (CaSO4). CFBC produces two kinds of spent bed materials, coarse bottom ash and a much finer fly ash. Both of these products are very high in calcium. When properly conditioned, these materials are capable of acting as hydraulic cements, forming both calcium aluminosulfate minerals, most importantly ettringite, as well as calcium-alumina-silica gels, …


Prediction Of The Unburned Carbon Content Of Fly Ash In Coal-Fired Power Plants, Saeid R. Dindarloo, James C. Hower Jan 2015

Prediction Of The Unburned Carbon Content Of Fly Ash In Coal-Fired Power Plants, Saeid R. Dindarloo, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Prediction of carbon content in fly ash is a valuable index in both designing and optimizing coal-fired boilers. In this study, methods of multiple regression (MR), decision trees (DT), and support vector regression (SVR) were used for prediction of unburned carbon content of fly ash in a 300-MW power plant with a tangentially fired furnace using a low-NOx concentric firing system. Twenty-one boiler operational and coal petrological variables from 21 experiments in a previous benchmark study were used. A variables correlation matrix was used for feature (independent variables) selection in order to reduce the dimensions (number) of input variables from …